Re: [PATCH 06/12] drm/xe/reg_whitelist: Report whitelist overflow using structured xe_log API

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Passing the positive error code `EPERM` instead of a negative error code (`-EPERM`) to `xe_log_err()` causes the error code to be silently dropped from the log output.
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--- Patch [6]: [PATCH 06/12] drm/xe/reg_whitelist: Report whitelist overflow using structured xe_log API ---
commit f104144be2febf4b75435938d8bb0126a65964c3
Author: Dnyaneshwar Bhadane <dnyaneshwar.bhadane@intel.com>

drm/xe/reg_whitelist: Report whitelist overflow using structured xe_log API

This commit replaces xe_gt_err() with the structured xe_log_err() API
when the maximum register whitelist slots are exhausted. It introduces the
REGS component tag to these log messages.

> diff --git a/drivers/gpu/drm/xe/xe_reg_whitelist.c b/drivers/gpu/drm/xe/xe_reg_whitelist.c
> index cab1b578ca0ef..d58c31b301991 100644
> --- a/drivers/gpu/drm/xe/xe_reg_whitelist.c
> +++ b/drivers/gpu/drm/xe/xe_reg_whitelist.c
[ ... ]
> @@ -186,9 +187,9 @@ static int whitelist_apply_to_hwe(struct xe_hw_engine *hwe, struct xe_reg_sr *in
>  		};
>  
>  		if (slot == RING_MAX_NONPRIV_SLOTS) {
> -			xe_gt_err(hwe->gt,
> -				  "hwe %s: maximum register whitelist slots (%d) reached, refusing to add more\n",
> -				  hwe->name, RING_MAX_NONPRIV_SLOTS);
> +			xe_log_err(hwe->gt, REGS, EPERM,

[Severity: Medium]
Will this drop the error code from the log message?

Looking at the xe_log_err macro definition:

#define xe_log_err(any, TAG, err, fmt, args...) \
	xe_log_comp_recoverable((any), TAG, ERR_PTR(err), 0, fmt, ##args)

The macro passes the error code wrapped in ERR_PTR(). If we pass a positive
value like EPERM, ERR_PTR(EPERM) will evaluate to false under the kernel's
IS_ERR() check, since only values in the [-MAX_ERRNO, -1] range are considered
valid errors.

This can cause the logging infrastructure to completely drop the error code
from the structured output.

Should this be passed as -EPERM instead?

> +				   "hwe %s: maximum register whitelist slots (%d) reached, refusing to add more\n",
> +				   hwe->name, RING_MAX_NONPRIV_SLOTS);
>  			break;
>  		}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260819191442.1957986-1-dnyaneshwar.bhadane@intel.com?part=6